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The present invention relates to printed circuit boards having conductive layers laminated to an insulating substrate and, in particular, to a connector system for such printed circuit boards making use of portions of the conductive layer as connector conductors.
Printed circuit boards are used to provide for the highly reliable and robust connection of circuit components. Such circuit boards substantially reduce the cost of interconnecting circuit components in contrast to point-to-point wiring, but nevertheless, often require point-to-point wiring through wiring harnesses between the circuit board and other vehicle components. Such harnesses can be costly and present additional points of possible failure both in the connection of the harness wiring to the printed circuit board conductors and in the connection of the harness wiring to the connector pins.
The present invention recognizes that point-to-point wiring harnesses may be avoided by using flexible circuit boards with short harness-like extensions connecting the circuit board to nearby components. The need for a crimp or solder-type connection between the harness-like extensions and connectors is eliminated by using the conductive layer of the printed circuit board as part of the connector in lieu of separate connector pins or sockets. The connector housing supports the normally malleable conductive layer of the printed circuit board providing the necessary rigidity and elasticity needed for connector conductors.
Specifically then, the present invention provides a circuit board connector assembly including a printed circuit board having a lower insulating substrate and an upper conductive layer. The upper conductive layer has at least one extenuate conductive finger bent upward. A connector half receives and supports the conductive finger, the connector half sized to mate with a corresponding connector half having a second conductive finger. The mating of the connector halves positions the conductive finger and second conductive finger in electrical contact.
Thus, it is one object of the invention to provide a connector system for printed circuit boards and does not require a separate electrical connection to be made between the conductors of the printed circuit board and the conductors of the connector. By using the conductive layer of the printed circuit board, a simple, robust and continuous conductive path is provided.
The conductive finger of the printed circuit board may be detached from the insulating substrate of the printed circuit board or alternatively, the insulating substrate of the printed circuit board may be cut around the conductive finger and both the conductive finger and its insulating substrate bent upward, the insulating substrate remaining attached to the upwardly bent conductive finger.
It is thus another object of the invention to provide a flexible system that may be adapted to printed circuit boards in which the conductive layer may be easily separated from its insulating substrate and to printed circuit boards in which the flexible substrate may be incorporated into the connector.
The conductive finger may be supported on the connector half by an electrically isolated pillar.
It is another object of the invention to obtain the necessary mechanical characteristics needed for connector conductors from the soft material of the conductive layer by using portions of the connector shell material to support the conductive finger.
The conductive finger may be longer than the height of the electrically isolated pillar and attached at its back surface to a first side of the electrically isolated pillar to bend over the top of the electrically isolated pillar and attach further to a second obverse side of the electrically isolated pillar.
Thus it is another object of the invention to provide for dual-sided electrical contacts in a connector while nevertheless providing the conductive finger with the necessary mechanical support.
The conductive finger may have a substantially rectangular cross-section with a back side, a front side, and a left and right edge and the electrically isolated pillar may include overhang portions that mechanically capture the left and right edges or alternatively or in addition, the end of the conductive finger.
Thus it is another object of the invention to provide for a strong mechanical attachment of the conductive finger to its dissimilar supporting member.
The end of the conductive finger may be beveled so as to provide a wedge-shaped engagement with the electrically isolated pillar.
Thus it is another object of the invention to provide for mechanical attachment of the conductive finger to the pillar such as may allow a smooth transitional surface between the two such as is desirable for sliding engagement of connector conductor members.
The electrically isolated pillar may include an elastomeric outer portion; the elastomeric outer portion may be convex.
Thus it is another object of the invention to provide for a greater xe2x80x9clead-inxe2x80x9d opening for connectors formed by this invention that may accommodate variations in part tolerance while ensuring good sliding contact between the conductive fingers.
The electrically isolated pillar and the conductive finger may be plated with a continuous metallic layer. A non-platable shroud may encase the lower portions of the electrically isolated pillar.
Thus it is another object of the invention to provide multiple conductive surfaces on the connector pins formed by the conductive finger and the electrically isolated pillar similar to conventional connector pin designs and further to allow plating of an assembled part without short circuits being created by the plating between multiple pins.
The connector may include downwardly extending barbs on the electrically isolated pillar sized to be inserted through a stabilizing support to mechanically fix the connector shell or the connector shell may be otherwise attached either through injection molding or other techniques to a mechanically stabilizing surface including but not limited to the substrate of the printed circuit board.
Thus it is another object of the invention to provide a good mechanical connection between the connector so formed and a base fixed relative to the printed circuit board so as to prevent undue tension or strain on the conductive layers forming the conductive finger.
The foregoing and other objects and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings, which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. Such embodiment does not necessary represent the full scope of the invention, however, and reference must be made to the claims herein for interpreting the scope of the invention.